1. Field of the Invention
The present invention relates to an image-processing device, an electronic camera, an image-processing program, and an image-processing method for correcting a luminance level of an image to be processed.
2. Description of the Related Art
Some digital still cameras perform various image processings on generated image data to achieve the function of an image-processing device. The image processings include: white balance adjustment; an interpolation processing; a color correction processing; a gradation correction processing; and the like. The gradation correction processing is generally realized by performing a gamma processing.
However, for an image to be processed (an image generated by a digital still camera) with a large difference in luminance, the conventional gamma processing may cause loss of gradation in the highlight and shadow areas of the image because it is uniformly performed on the entire image, which results in depriving characteristics of details of the image. Moreover, in the case where the image to be processed has a small difference in luminance, the gamma processing may degrade contrast of the entire image, and make the image weak in gradation.